Parallel and Series/Parallel Circuits   Objectives:             Upon completion of this lab, you should be able to: Measure current, Voltage, and Resistance using a…

 

Parallel and Series/Parallel Circuits

 

 

 

Objectives:

 

            Upon completion of this lab, you should be able to:

 

• Measure current, Voltage, and Resistance using a multi-meter

• Use basic electrical laws including Ohm’s Law, Kirchhoff’s Voltage Law and the Power equation to analyze electrical circuits.

• The student will solve direct current (DC) series, parallel, and series-parallel networks.

 

 

 

Materials:

 

1 x	Elvis Unit with:   Variable Power Supply    Prototyping board	1 x	Digital Multi-Meter    Fluke 179 or equivalent
1 x	22 Ω, 100 Ω, 220 Ω, 330 Ω, 1.1k Ω

 

 

 

 

 

Discussion:

 

Electrical circuits are commonly arranged in discreet or combinational series and parallel configurations.  Series circuits can be identified by circuits or portions of circuits that allow only a single path for current.  As a result, series circuits have multiple voltage drops across the components associated with the distribution of voltage within the circuit.  Parallel circuits on the other hand are identified in circuits or portions of circuits that allow multiple paths for current to flow.  Because multiple paths exist, a common voltage is present across each “branch” of the circuit. 

 

 

 

 

 

Procedure:

Series-Parallel Circuit Analysis

 

1. Identify the color code associated with each resistor listed in table 1 below.  Measure and record the values of the 22 Ω, 100 Ω, 220 Ω, 330 Ω and 1.1 k Ω using the DMM.

2. Measure and record the output of the +15 V power supply using the DMM and record the voltage in the last column of table 1.

    

 

Table 1
Nominal	22 Ω	100 Ω	220 Ω	330 Ω	1.1 k Ω	+15 V
Color Code
Measured

 

 

 

 

1. Use any method available to analyze the circuit to the right in order to determine each quantity listed below in table 2.

    

2. Construct the circuit and measure the total circuit resistance with the circuit disconnected from the
   +15 V Source.  Record this measurement in table 2.

    

3. Connect the circuit to the source and apply power.  Measure and record each quantity listed below.

 

 

 

 

 

1. Repeat Steps 3 through 5 for the circuit illustrated to the right and record values in table 3.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Questions:

 

1. Provide a description of the method that was used to analyze the first circuit? 

2. Use the data collected in the second table to show that Kirchhoff’s Voltage and Current Law were satisfied.

3. Provide a description of the method that was used to analyze the second circuit? 

4. Using at least two separate loops, use the data collected in the third table to show that Kirchhoff’s Voltage Law was satisfied.

5. Explain why it was not possible to use simplification to analyze the second circuit.

 

 

 

 

Simulation Exercise

 

 

 

This simulation exercise will give you an opportunity to construct your first circuit in MultiSim.  It will provide you an opportunity to use functionality that has previously been introduced in earlier labs to confirm the analysis of a series-parallel combinational circuit.

 

 

 

Procedure:

 

 

 

1. Calculate the total resistance of the circuit to the right and record the resistance in the space provided.

 

 

 

 

 

 

 

1. Construct the circuit to the right in MultiSim and use a Virtual Ohm-meter to measure the total circuit resistance. The virtual multimeter is located near the top of the virtual instruments palette on the right side of the workspace.

 

 

 

 

 

 

 

1. Analyze the circuit using the simplification process introduced in class and determine each quantity below.  Record the results in the first column of the table below.

 

	Calculated Results	Simulated Results

 

 

 

 

 

1. Use MultiSim to verify each calculated quantity in step 3 and record in the right-hand column of the table above.

 

 

 

 

 

 

Questions:

 

 

 

1. Did the circuit used for the simulation exercise simplify to a series equivalent or parallel equivalent circuit?

2. How close did your calculated results correspond with those found using MultiSim.  Explain any variation between your results and MultiSim’s results.

How did the variation between the simulated exercise and calculations compare to the measured and calculated results from table 2 in the first part of the lab